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-   -   Car does not set back to idle for 2-3 seconds. (https://www.rctech.net/forum/nitro-off-road/338410-car-does-not-set-back-idle-2-3-seconds.html)

xnitrorc 10-24-2009 06:49 AM

Car does not set back to idle for 2-3 seconds.
 
Hi Guys,

Something weird is happening with my VRX-2 when i give it full throttle and release it so it runs back to idle the servo returns back to idle position. The carburetor also fully shuts of so no air is getting through from what i can see.

Also it seems to be running still on half throttle but only for a few seconds, it seems to be burning fuel as well. Not come across this problem before at 1st i thought it may be a radio problem but its not and nothing is keeping the air intake open.

As far as i can see there must be some sort of air leak in the carburetor, but it is also burning fuel.

Any ideas?

blktransam 10-24-2009 07:05 AM

use the search button...or look at the top of this page under the "tuning bible"...but sounds as if the low end is rich and high end is a little lean and then loading up after a couple seconds dropping the idle down...from what it sounds like you need torichen up the op end a coule hours and lean out the low end until you get a steady "higher then normal idle" and then re adjust your idle speed screw to drop the idle down.

Ryan

madweazl 10-24-2009 07:16 AM

If the throttle feels like it's hanging up after a full throttle run you're probably lean on the high side needle; I had the same issue a few weeks ago. I was also too rich on the bottom and was seeing temps in the 215 range even though I was lean up top.

awdcameolsx 10-24-2009 07:19 AM


Originally Posted by blktransam (Post 6513904)
use the search button...or look at the top of this page under the "tuning bible"...but sounds as if the low end is rich and high end is a little lean and then loading up after a couple seconds dropping the idle down...from what it sounds like you need torichen up the op end a coule hours and lean out the low end until you get a steady "higher then normal idle" and then re adjust your idle speed screw to drop the idle down.

Ryan

+1 to this I had the same problem at one point this year. I richened the top 6 hours, reset the low and idle, till it acted like it should then race tuned from there. About half the "air leak" problems I have seen where actually tuning problems.

coviello 10-24-2009 09:20 AM

he cant tune a motor. but he wants to set the world record for the farthest jump?

blktransam 10-24-2009 09:22 AM

sounds like it...

Frank L 10-24-2009 09:43 AM

+2 on the top too lean. When the throttle is wide open the high speed needle descides how much fuel goes to the engine if there is not enough then when you let off it will have a lean eeeeeeeeeeee sound until it has enough fuel to drop the idle down. Try richening 1 hour and then run it for 2 - 3 minnand recheck. Make sure you always run the car inbetween carb adjustments.

houston 10-24-2009 10:00 AM

It probably screams down the straights (or on the street) though !! ;)

blktransam 10-24-2009 10:08 AM

high end needle controls the fuel at wot, low end controls fuel at idel and at take off...liek I said it prb. a combination of lean top end and rich low end.

casevac 10-24-2009 10:18 AM

Lean the idle gap and LSN... Don't mess with HSN

xnitrorc 10-24-2009 10:25 AM

Whats wrong with asking?
 

Originally Posted by coviello (Post 6514274)
he cant tune a motor. but he wants to set the world record for the farthest jump?

A blind person can't see but they can play musical instruments better than most sited people.

Nothing wrong with wanting to learn

xnitrorc 10-24-2009 10:38 AM

Thanks
 
Hi All,

Ill have a play around with the HSN i know its set to lean because the engine overheats and hesitates after a tank of fuel. Didn't think this would have an affect on the return to idle.

Thanks Guys

houston 10-24-2009 12:29 PM


Originally Posted by xnitrorc (Post 6514505)
Hi All,

Ill have a play around with the HSN i know its set to lean because the engine overheats and hesitates after a tank of fuel. Didn't think this would have an affect on the return to idle.

Thanks Guys

all the needles effect each other , some minimal , some much more .

once you find a balance in the carb (novas) it is usually pretty close to in the ball park and may need minor tweaks either way but the balance will stay pretty close .

such as lean the high speed and richen low speed or richen high speed and lean low speed . adjust idle to suit .


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